| (19) |
 |
|
(11) |
EP 0 252 528 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
05.07.1989 Bulletin 1989/27 |
| (43) |
Date of publication A2: |
|
13.01.1988 Bulletin 1988/02 |
| (22) |
Date of filing: 31.10.1984 |
|
| (51) |
International Patent Classification (IPC)4: E21B 7/08 |
|
| (84) |
Designated Contracting States: |
|
BE GB SE |
| (30) |
Priority: |
01.11.1983 GB 8329138
|
| (62) |
Application number of the earlier application in accordance with Art. 76 EPC: |
|
84903975.5 / 0160678 |
| (71) |
Applicant: ENCORE DRILLING COMPANY LIMITED |
|
Leamington Spa
Warwickshire CV33 OJH (GB) |
|
| (72) |
Inventors: |
|
- Braithwaite, Richard William
Rugby
Warwickshire. CV23 8NW (GB)
- Smith, Graham Malcolm
Coventry, CV5 7JJ (GB)
- Bellamy, Norman West
Coventry, CV3 6ES (GB)
- Gergely, Stephen
Coventry, CV3 6GB (GB)
|
| (74) |
Representative: Wilson, Nicholas Martin et al |
|
WITHERS & ROGERS
4 Dyer's Buildings
Holborn
London EC1N 2JT
London EC1N 2JT (GB) |
|
| |
|
| (54) |
Improved drilling method and apparatus |
(57) A retrievable or fixed wedging assembly for steering or branching a borehole is provided
in which the assembly is locked in position by means of an annular locking means which
engage about the wall of the borehole at the desired position.